Please be aware that Jakarta has multiple airports and that these results are for all airports serving the city.
The best month to fly between Jakarta and Kupang is February and the most expensive month to fly is December. (Average prices, based on 5821 datapoints.)
The best day to arrive at Jakarta is Friday and it would be best to avoid Monday, as prices are on average 4.69% higher than on Friday. (Average prices, based on 5821 datapoints.)
The best time to fly is at around 2. (Average prices, based on 14037 datapoints.)